The production effect has been shown to result in a robust benefit for memory (Conway & Gathercole, 1987; Dodson & Schacter, 2001; Gathercole & Conway, 1988; Hopkins & Edwards, 1972; MacDonald & MacLeod, 1998; MacLeod et al. 2010). Saying aloud some of what is studied makes that portion more memorable. MacLeod et al. (2010), inspired by Conway and Gathercole (1987; Gathercole & Conway, 1988), have argued for distinctiveness as the best explanation of the benefit—that retrieval of the fact that an item was said aloud during study is used to confirm that the item was indeed studied. Ozubko and MacLeod (2010) provided evidence that distinctiveness is the “active ingredient” in the production effect, and Ozubko et al. (2011) provided evidence for the roles of both recollection and familiarity.
Until now, all studies of the production effect have compared self-performed production to no production; that is, each individual participant has read a word aloud or has read a word silently. The present study was designed to examine whether production by another person would also result in a memory benefit, and if so, what the relative benefits would be. These two experiments revealed that there is a “gradient” of benefit brought about by the production effect—from self-production, to joint production with another person, to production only by another person, to silent reading only—and that this gradient is consistent and reliable. Clearly, the production effect is largest when it is self-performed.
The both condition is particularly intriguing. Under the present explanation, its benefit being intermediate between other and self production is not seen as social loafing occurring during encoding. Instead, it is interpreted as being due to disruption of the distinctiveness that arises from personal production: The test of distinctiveness at the time of retrieval is no longer conclusive when production at encoding was not unique to oneself. This idea has precedent in the work of Basden, Basden, Bryner, and Thomas (1997), who suggested that interfering with an individual’s unique retrieval strategy impairs remembering. Note, however, that their account relied solely on activity at retrieval, whereas the production effect is seen as occurring due to the interaction of encoding and retrieval.
Very recently, Barber, Rajaram, and Aron (2010) presented evidence of a cost at encoding due to collaboration with another individual. Participants were asked to produce a sentence linking two words (e.g., citizen–trail), with one participant creating the first part of the sentence (e.g., the citizen went) and the other creating the second part (e.g., along the trail) versus a single participant creating the whole sentence. On a subsequent cued recall test, memory was superior for participants who had encoded individually than for those who had encoded collaboratively. Barber et al. argued that “collaborative encoding produces less effective cues for later retrieval” (p. 255). This disruption at encoding fits with what happened in the present experiments when both individuals produced responses. In place of cue effectiveness, one need only substitute distinctiveness of the additional dimension of encoding—that the word was produced—to align the accounts. Indeed, it is quite possible that differential distinctiveness provides a mechanism for differential cue effectiveness.
It is clear, then, that the production effect robustly extends to situations in which another person does the production, but that the benefit is largest when the production is done by oneself. Recollection of one’s own production at the time of test is optimally distinctive, in part because individuals may focus on their own productions to verify that an item was previously studied. Any other production, therefore, is less distinctive: Indeed, the participants in these experiments did report routinely trying to remember whether they had produced an item themselves, but not routinely doing so for items produced by the other person. The likelihood of using the distinctiveness heuristic increases as production—the aspect of processing at study that can be retrieved—becomes increasingly personal and unique.
This analysis may resolve a discrepancy considered in the introduction: Modality does not typically influence long-term retention, whereas production does. Why would auditorily presented words not be remembered better than visually presented words when words spoken aloud are remembered better than those read silently? By the present account, when modality is manipulated, words are presented either auditorily or visually, so additional modality information is present for both sets of items. In contrast, when production is manipulated, all items are presented visually, but some have the additional dimension of encoding that they were also produced aloud. This additional element provides the basis for a test of prior experience that goes beyond the item information. Add to this the more personal element of the items being produced by oneself or by another nearby person, and this may well explain why production causes a benefit, but auditory presentation does not.
In recent years, the embodied cognition perspective has come to the fore (see, e.g., Robbins & Aydede, 2009). This approach emphasizes that cognition is a situated activity, replacing the idea of cognition as computation involving a set of formal operations applied to abstract symbols. As Anderson (2003, p. 91) maintained, “thinking beings ought therefore be considered first and foremost as acting beings.” This idea is certainly relevant to language, and reveals itself in many ways, such as in the added value of thinking aloud in intelligent problem solving (e.g., Fox & Charness, 2010). Under the embodied view, the production effect gains its value from the action of producing. The activity of another person producing can certainly be processed and used for remembering, but one’s own actions are more direct, more distinctive—more embodied—and hence more memorable due to their uniqueness.